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A new study from the US has reckoned that doubling serum levels of 25­hydroxyvitamin D showed to be the “most cost-effective way to reduce global mortality”.

The paper assessed the presumable impact on mortality rates of increasing serumvitamin D levels from 54 to 110 nmol/L in six geopolitical regions around the world: Africa, the Americas, Eastern Mediterranean, Europe, Southeast Asia and Western Pacific (1). The author identified and considered major vitamin D sensitive diseases with incidence and mortality rates that are reduced by higher serum 25(OH)D levels: e.g., cancer, cardiovascular disease (CVD), diabetes mellitus, bacterial and viral infections, musculoskeletal diseases and neurological diseases. To make his calculation, he referred to a wide range of forms of evidence, including epidemiological studies as – what he considered to be – a reliable base. He adopted the mean serum level of 54 nmol/L for each global region for use in his study on the basis of a meta-analysis of cross-sectional studies on global serum 25(OH)D status. The mortality rates for the various regions were obtained from World Health Organization (WHO) data from 2004. He calculated a reduction in the mortality rate for each region on the basis of death rates and vitamin D dose-response relations. The author postulates all-cause mortality rates dropping to a range of between 7.6% for African females to 17.3% for European females.

The study identified strong evidence that vitamin D intake can reduce mortality in the case of many diseases: e.g., CVD, respiratory infections and diseases, some cancers, multiple scleroses, falls and fractures and diabetes. For diabetes type II, the growing evidence for risk reduction with vitamin D was confirmed recently by a new review (2). This included eight observational studies and eleven randomized controlled trials. The meta­analysis of the observational studies showed that risk of diabetes type II decreased by 13% with vitamin D intake of >500 international units (IU) per day compared with a daily intake of <200 IU.

The author of the aforementioned study stated the several ways to raise serum 25(OH)D levels among the population: to increase food fortification (although, he points out that it is difficult to provide a high enough dosage), to make vitamin D supplements more readily available (although, probably not everybody at risk would take them) and to promote production of vitamin D from UVB-radiation (weighing the adverse effects against the positive health effects). He argued for more agreement between health policy makers; saying, “vitamin D has many health benefits and that society would benefit from higher levels” if there was a move “to implement policies to increase serum 25(OH)D levels at the national or regional level”.

References

Grant W.B. An estimate of the global reduction in mortality rates through doubling vitamin D levels. European Journal of Clinical Nutrition 2011.